<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        #id01,.class01{
            border: 1px solid yellow;
            color: blue;
            font-size: 20px;
        }
        a{
            text-decoration: none;
        }
    </style>
</head>
<body>
    <div id="id01">第一个div</div>
    <span class="class01">第一个span</span>
    <a href="http://www.baidu.com">百度</a>
</body>
</html>